1. Technical Field
This invention relates to cold weather garments, and more particularly to an electrically heated cold weather garment and electronic control system and method therefor for controlling electric heating levels within the garment.
2. Discussion
Electrically heated garments, or portions thereof, are helpful in combating the effects of cold temperatures on a person subjected to prolonged exposure to the cold. More specifically, a heated garment can prove helpful to persons such as sportsmen, farmers, construction workers, public officials, military personnel, etc., who frequently are exposed to cold weather for prolonged periods of time.
Problems with prior art electronic control systems for electrically heated garments have existed with respect to the ability to heat a plurality of discrete heating zones of the garment independently. Heating different zones individually with a high degree of control is desirable because of the varying rate at which different parts of the body lose heat. The extremities, i.e., hands, feet and head, for example, suffer from a greater heat loss than the torso. In addition, physical activities of the wearer of the garment can cause different parts of his body to generate heat at varying levels. A system which applies the same level of heat to all areas of the garment can therefore produce temperature levels within the garment that are uncomfortable to the wearer.
Prior art electronic control systems, to be able to control the heat applied to various zones of the garment independently, typically require an independent, user actuatable switch for each zone to enable or interrupt the current flowing to its associated heating element or elements. In these systems the control of the wearer over the amount of heat generated by the various heating elements of the suit is quite limited., the heating elements are either fully on or fully off, thereby generating either maximum heat or no heat at all. In some prior art systems, attempts have been made to provide variable control over the heat generated by each heating element by using switches to selectively connect a power source to a plurality of heating elements having different heat generating capabilities or characteristics. In this manner some control is allowed over the amount of heat generated for a particular zone of the garment, but still only in fixed steps.
Another drawback of many prior art heated garments is the fabric used for the garment itself. Ideally, the fabric should be light in weight and not bulky to minimize the loss of flexibility during physical activities of the wearer. The fabric itself should also have excellent insulating capabilities, be stretchable, and be capable of rapidly absorbing and evaporating moisture and perspiration from the skin of the wearer. Many prior art heated garments suffer from a lack of one or more of these features. Various prior art heated garments and component parts thereof may be found in the following U.S. Patents:
______________________________________ U.S. Pat. No. Issued Inventor(s) ______________________________________ 710,429 1902 Collins et al 1,284,378 1918 A. Lemercier 1,328,229 1920 F. Hewitt 1,655,838 1928 E. Lackland 1,761,829 1930 O. Heinemann 1,820,602 1931 T. Dick 2,329,766 1943 W. Jacobsen 2,460,433 1949 E. Ripley 2,579,383 1951 F. Goudsmit 2,858,410 1958 C. Rich 3,084,241 1963 Carrona 3,134,891 1964 M. Hyer 3,293,405 1966 R. Costanzo 3,663,797 1972 R. Marsh 3,729,613 1973 R. Deloire et al 3,751,620 1973 T. Yuasa 3,781,514 1973 M. Olson et al 3,858,028 1974 J. Kerr 3,946,193 1976 E. Giese 4,087,675 1978 C. Sansonetti 4,404,460 1983 J. Kerr 4,665,308 1987 G. Courvoisier et al 4,713,531 1987 Fennekels et al ______________________________________
While each of the above systems, or portions thereof, operate with varying degrees of effectiveness, it would nevertheless be desirable to have an electrically heated cold-weather garment having a plurality of discrete heating zones. It would further be desirable if such a garment were to incorporate a lightweight, stretchable, form-fitting fabric which would allow the wearer of the garment excellent flexibility and range of movement when performing a variety of physical activities.
It would further be desirable if such a garment were to include a plurality of flexible electrical conductors arranged in a predetermined fashion to generate heat evenly throughout a particular area, or zone, of the garment. The utility of the suit would also be increased if the conductors were independent, such that a break in one conductor would not affect the heat generating capabilities of conductors for other areas or zones of the garment. An additional desirable feature of such a garment would be the incorporation of a plurality of independent connectors for independently connecting the heat generating conductors with a power source. Such a plurality of connectors would further help to enable many of the conductors to remain operating if one of the conductors were to break and cease operating.
It is therefore an object of the present invention to provide a lightweight, stretchable, form-fitting fabric for use in connection with an electrically heated, cold-weather garment, which is flexible and allows excellent range of movement to a wearer of the garment.
It is an additional object of the present invention to provide a garment assembly having a plurality of independent conductors, with each conductor being arranged in a predetermined fashion within a particular heating zone of the garment, to thereby heat evenly the particular zone.
It is still a further object of the present invention to provide an electrically heated garment having a plurality of connectors for connecting the conductors of the garment to an external power source. Such a plurality of connectors would thereby enable heat to be supplied to one area or zone of the garment even if a different conductor were broken, and thus would further add to the utility and durability of the suit.
It is another object of the present invention to provide for an electrically heated garment having the conductors thereof securely attached to the fabric of the garment in such a fashion as to hold securely thereto the conductors.
It is still another object of the present invention to provide for an electrically heated garment having an electronic control system operable to independently and simultaneously, and in uniform fashion, control the current flow through each conductor of the garment.